67 S-Code Timing Vacuum

[jimeast]

My understanding is the 67 390 S-Code uses manifold vacuum via a tube on the carb spacer for the vacuum advance on the distributor.  My car has the vacuum line from the distributor going to a port on the front metering block on the passenger side and the port on the carb spacer seems to unused and open to the world. I need to rebuild the carb anyhow, and will also correct this, but I thought I'd ask what kind of problems running the car like this would cause? 

[cammerfe]

Several thoughts---

First, if you truly have the opening at the base open to atmosphere, you have a serious vacuum leak. Your idle must suffer significantly.
Second, I've never owned a '67 390, but I'm sure others will agree that the port in the metering block is the correct place to pull vacuum for timing purposes.

Good luck!

KS

[jimeast]

I've been reading up a little on general vacuum requirements, and port vs manifold vacuum.  I might be mistaken, but I thought the '67 might be the last year to use manifold vacuum vs port. (which would imply mine is set up wrong)  The carb spacer for the '67 is specific to that year, the spacers for '68, and '69 not have vacuum line port in them.

http://www.mansfieldmustang.com/03-17.JPG

[jimeast]

I was just told by the owner at Mansfield Mustang that the port in the carb spacer is not used (should be plugged),  Also the vacuum advance is port vacuum from the carb plate as mine is.  CammerFE, kudos for knowing your stuff.  So... I was wrong on all counts.  However I do need to get the carb spacer port plugged with a rubber plug.

[Faron]

Ford NEVER Used Manifold Vacuum , always Ported/timed , leave it at the metering Block , Have The Dist Recurved if you want to Optimize the Performance